Journal ArticleDOI
Correcting astigmatism with toric intraocular lenses: Effect of posterior corneal astigmatism
TLDR
Corneal astigmatism was overestimated in WTR by all devices and underestimated in ATR by all except the Placido–dual Scheimpflug analyzer.Abstract:
Purpose To evaluate the impact of posterior corneal astigmatism on outcomes with toric intraocular lenses (IOLs). Setting Cullen Eye Institute, Baylor College of Medicine, Houston, Texas, USA. Design Case series. Methods Corneal astigmatism was measured using 5 devices before and 3 weeks after cataract surgery. Toric IOL alignment was recorded at surgery and at the slitlamp 3 weeks postoperatively. The actual corneal astigmatism was calculated based on refractive astigmatism 3 weeks postoperatively and the effective toric power calculated with the Holladay 2 formula. The prediction error was calculated as the difference between the astigmatism measured by each device and the actual corneal astigmatism. Vector analysis was used in all calculations. Results With the IOLMaster, Lenstar, Atlas, manual keratometer, and Galilei (combined Placido–dual Scheimpflug analyzer), the mean prediction errors (D) were, respectively, 0.59 @ 89.7, 0.48 @ 91.2, 0.51 @ 78.7, 0.62 @ 97.2, and 0.57 @ 93.9 for with-the-rule (WTR) astigmatism (60 to 120 degrees), and 0.17 @ 86.2, 0.23 @ 77.7, 0.23 @ 91.4, 0.41 @ 58.4, and 0.12 @ 7.3 for against-the-rule (ATR) astigmatism (0 to 30 degrees and 150 to 180 degrees). In the WTR eyes, there were significant WTR prediction errors (0.5 to 0.6 diopters [D]) by all devices. In ATR eyes, WTR prediction errors were 0.2 to 0.3 D by all devices except the Placido–dual Scheimpflug analyzer (all P Conclusions Corneal astigmatism was overestimated in WTR by all devices and underestimated in ATR by all except the Placido–dual Scheimpflug analyzer. A new toric IOL nomogram is proposed. Financial Disclosure Drs. Koch, Weikert, and Wang received research support from Ziemer USA, Inc. Dr. Koch has a financial interest with Alcon Laboratories, Inc., Abbott Medical Optics, Inc., Optimedica Corp., and Ziemer USA, Inc. No other author has a financial or proprietary interest in any material or method mentioned.read more
Citations
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Journal ArticleDOI
Astigmatism Profile in a Large Series of Brazilian Patients
TL;DR: The mean magnitude of the anterior, posterior, and total corneal astigmatism was 1.50 ± 1.11, 0.34 ± 0.15, and 1.29± 0.98 diopters, respectively as discussed by the authors .
Proceedings ArticleDOI
Development of a universal toric intraocular lens calculator
David Hjelmstad,Samir I. Sayegh +1 more
TL;DR: This work presents a method for calculating the ideal toric lens to implant in astigmatic patients following cataract surgery, and combines the spherical and cylindrical power calculations into one, and allows for lens data from any manufacturer to be used, eliminating the reliance on multiple programs.
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Evaluation of the Relationship between Incision Location and Change of Posterior Corneal Astigmatism
TL;DR: “방향” 투명각막절개를 통해 시행된 초음파수정체유화술을 받은 환자 81 명(84안)을
Journal ArticleDOI
Torische Kunstlinsen zur Astigmatismuskorrektur
Oliver Findl,Nino Hirnschall +1 more
TL;DR: Toric intraocular lenses allow a reduction of corneal astigmatism during cataract surgery, which is evidence based and easy to correct to correct very low amounts ofAstigmatism.
References
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Contribution of posterior corneal astigmatism to total corneal astigmatism.
Douglas D. Koch,Shazia F. Ali,Mitchell P. Weikert,Mariko Shirayama,Richard B. Jenkins,Li Wang +5 more
TL;DR: Selecting toric intraocular lenses based on anterior corneal measurements could lead to overcor correction in eyes that have with‐the‐rule astigmatism and undercorrection in eyes which have against‐the-ruleAstigmatism.
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TL;DR: Analytical methods for evaluating the results of keratorefractive surgical procedures and emphasize the importance of intraocular astigmatism and the limitations of manual keratometry are demonstrated.
Journal ArticleDOI
Foldable toric intraocular lens for astigmatism correction in cataract patients.
TL;DR: The results indicate that phacoemulsification and posterior chamber AcrySof toric IOL implantation is an effective option to correct preexisting astigmatism in cataract surgery.